KR20100002771A - Control method of multi-type air-conditioning system - Google Patents

Abstract

PURPOSE: A control method of a multi-type air-conditioning system is provided to increase switching success yield of a four-way valve by driving a compressor of an outdoor unit with minimum frequencies or turning off. CONSTITUTION: A four-way valve of each outdoor unit are switched, a first high-low pressure difference of the outdoor unit are measured at after the operation of a first compressor, and then the first high-low pressure difference is judged to be over a first reference pressure(S100,S102,S104). If the first high-low pressure difference does not exceed the first reference pressure, a second high-low pressure difference is detected after the operation of a second compressor(S108). Until the first and second compressors are operating for a specified time, it is judged that the second high-low pressure difference exceed a second reference pressure(S110,S114). If the second high-low pressure difference does not exceed the second reference pressure, the operation of the first compressor of the outdoor unit which secures one of the first or second high-low pressure differences is controlled(S116). It is judged that a third high-low pressure difference exceeds a third reference pressure(S118). If the third high-low pressure difference does not exceed a third reference pressure, it is judged as switching error of a four-way valve and a system is turned off or re-started(S120,S126,S124).

Description

Control method of multi-type air-conditioning system

The present invention relates to a control method of a multi-air conditioning system, and more particularly, to a control method of a multi-air conditioning system that is easy to switch the four-way valve at the start of the compressor.

In general, an air conditioner is a home appliance for maintaining indoor air in a state most suitable for use and purpose. For example, in summer, the room is cooled to a cool state, in winter, the room is heated to a warm state, and also the humidity of the room, and the air in the room to a clean state of clean. As life convenience products such as air conditioners are gradually expanded and used, consumers are demanding high energy use efficiency, performance improvement and convenience products.

Such an air conditioner includes a separate air conditioner in which an indoor unit and an outdoor unit are separately separated, an integrated air conditioner in which the indoor unit and the outdoor unit are combined into one device, a wall-mounted air conditioner and a frame type air conditioner configured to be mounted on a wall, and a living room. A slim air conditioner configured to stand, a single air conditioner configured to be used in a small place such as a house, and a large air capacity configured to be used in a company or a restaurant. It is divided into an air conditioner and a multi type air conditioner having a capacity capable of sufficiently driving a plurality of indoor units.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control method of a multi-air conditioning system, in which switching of four-way valves is easy when the compressor is started.

In the control method of the multi-air conditioning system of the present invention, the four-way valve of each outdoor unit is switched and the first high and low pressure difference of each outdoor unit is measured after the operation of the first compressor, so that the first high and low pressure difference exceeds the first reference pressure. In the first determination step of determining, in the first determination step, if the first high and low pressure difference of at least one outdoor unit does not exceed the first reference pressure, the second high and low pressure difference is driven after operating the second compressor of the outdoor unit. A second determination step of determining whether the second high and low pressure difference exceeds a second reference pressure until the first and second compressors are operated for a preset time; and in the second determination step, the second determination step If the high and low pressure difference does not exceed the second reference pressure, controlling operation of the first compressor of the outdoor unit in which one of the first and second high and low pressure differences is secured, measuring the third high and low pressure difference of the corresponding outdoor unit, and Third high and low pressure difference In the third judging step and the third judging step of determining whether or not the reference pressure is exceeded, if the third high and low pressure difference does not exceed a third reference pressure, it is determined as a switching error of the four-way valve and the system is turned off or restarted. Steps.

In the control method of the multi-air conditioning system of the present invention, when the four-way valve is not switched due to the difference in the compressor starting time or the foreign matter of the four-way valve when the compressor of each outdoor unit is started, the compressor of the outdoor unit other than the outdoor unit that fails to switch the four-way valve is operated. By operating at an off or minimum frequency, it is possible to increase the success rate of switching of the four-way valve and to secure the differential pressure of the outdoor unit in which the four-way valve switching fails, thereby improving the stability of the driving cycle and the cooling and heating speeds.

A multi-air conditioning system and a control method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a multi-air conditioning system according to a first embodiment of the present invention.

Referring to FIG. 1, the multi-type air conditioner of the present invention includes an outdoor unit connected to a plurality of indoor units 11, 12, 13, and 14, and a plurality of indoor units 11, 12, 13, and 14. 21, 22).

Here, the plurality of indoor units (11, 12, 13, 14) and the outdoor unit (21, 22) is connected through a refrigerant pipe (not shown), the outdoor unit (21, 22) is a plurality of indoor units (11, 12, 13, 14) and the outdoor unit 21, 22 is driven by the request of at least any one, the operation of the outdoor unit (21, 22) as the cooling / heating capacity required by the plurality of indoor units (11, 12, 13, 14) increases The number and operation number of the compressors installed in the outdoor units 21 and 22 are increased.

Here, the plurality of indoor units 11, 12, 13, and 14 are an indoor heat exchanger 51 for exchanging refrigerant and indoor air, and an indoor blower 52 disposed near the indoor heat exchanger 51 to circulate indoor air. And an indoor expansion valve 54 for expanding the refrigerant flowing to the indoor heat exchanger 51 during cooling.

Each of the outdoor units 21 and 22 receives an accumulator 61 which extracts only a gas refrigerant from the refrigerants supplied from the plurality of indoor units 11, 12, 13, and 14, and receives and compresses the gas refrigerant extracted from the accumulator 61. The compressors 62 and 63, the four-way valves 65 connected to the first and second compressors 62 and 63 to select a flow path of the compressed refrigerant, and the refrigerant and the outdoor air supplied from the four-way valves 65. It includes an outdoor heat exchanger 70 for heat exchange.

Here, the outdoor unit (21, 22) is provided with an inverter compressor (62) and a constant speed compressor (63), the inverter compressor (62) is a compressor that can vary the compression capacity of the refrigerant, the constant speed compressor (63) of the refrigerant Compressor with constant compression capacity.

On the other hand, the oil separator 64 is installed in the pipe connecting the compressors 62 and 63 and the four-way valve 65, and the oil separator 64 is connected to the suction side of the compressors 62 and 63.

In particular, the oil separator 64 separates the oil from the refrigerant discharged from the compressors 62 and 63, and supplies the separated oil to the compressors 62 and 63, thereby providing an appropriate amount of oil in the compressors 62 and 63. Keep it. Then, the suction side pipes of the oil separator 64 and the compressors 62 and 63 are connected through the capillary tube 66, and the oil is moved through the capillary tube 66.

In addition, the refrigerant pipes guiding the refrigerant discharged from the outdoor heat exchanger 70 to the indoor heat exchanger 51 include outdoor electromagnetic expansion valves lev and 74 for expanding the refrigerant during heating, and an indoor heat exchanger 51 for cooling. Subcooling apparatus 80 for cooling the refrigerant moved to the liquid, and a liquid injection device 90 for lowering the temperature of the compressor (62, 63) is provided.

Here, the outdoor electromagnetic expansion valve 74 is fully open during cooling to allow the refrigerant condensed in the outdoor heat exchanger 70 to pass through without expansion, but when heated, it is opened to a predetermined size and condensed in the indoor heat exchanger 51. Before expanding to the outdoor heat exchanger (70) to the liquid in the spray state.

Here, the indoor electromagnetic expansion valve 54 and the outdoor electromagnetic expansion valve 74 is provided with a step motor (not shown) therein, and operates under control from a controller (not shown).

At this time, during the cooling and heating, the step motors of the indoor electromagnetic expansion valve 54 and the outdoor electromagnetic expansion valve 74 operate under the control of the controller.

2 is a block diagram of the outdoor unit side cooling cycle in the multi-air conditioning system according to the present invention.

Referring to Figure 2, this multi-air conditioning system has been described with three outdoor units (A, B, C), but is not limited.

The first and second compressors 62_A, 62_B, 62_C, 63_A, 63_B, and 63_C, which supply high-temperature, high-pressure gas refrigerant to the outdoor units A, B, and C of the multi-air conditioning system, may be used for cooling or heating. Four-way valves (65_A, 65_B, 65_C) to switch the flow, the indoor heat exchanger (not shown) acts as a condenser when the refrigerant acts as a condenser, and when the indoor heat exchanger acts as a heater, the refrigerant evaporates The working outdoor heat exchangers 70_A, 70_B, 70_C and expansion valves (not shown) for expanding the refrigerant to low temperature and low pressure are respectively provided.

In the cooling operation of the multi-air conditioning system, the gas compressed in the first and second compressors 62_A, 62_B, 62_C, 63_A, 63_B, and 63_C passes through a component such as an oil separator (not shown) to allow the four-way valve 65_A to operate. After the gas refrigerant flows into the high pressure part of the fuel cell, 65_B and 65_C, the gas refrigerant introduced into the outdoor heat exchanger 70_A, 70_B and 70_C through the connection part is condensed and then passes through the expansion valve and passes through the refrigerant pipe P_1 to the plurality of indoor units ( (Not shown).

The gas evaporated while passing through the indoor heat exchanger passes through the connection part of the four-way valves 65_A, 65_B, and 65_C and the low pressure part through the refrigerant pipe P_2 connected to the outdoor units A, B, and C. 62_A, 62_B, 62_C, 63_A, 63_B, 63_C) are returned to the suction part.

On the contrary, in the heating operation, the gas discharged from the first and second compressors 62_A, 62_B, 62_C, 63_A, 63_B, and 63_C passes through the high pressure part and passes through the connection part of the four-way valves 65_A, 65_B, 65_C and then the refrigerant pipe. It is supplied to the plurality of indoor units through (P_2). The liquid refrigerant condensed in the indoor heat exchanger flows into the outdoor units (A, B, C) through the refrigerant pipe (P_1), expands through the expansion valve, and then evaporates in the outdoor heat exchangers (70_A, 70_B, 70_C). And flows into the inlets of the first and second compressors 62_A, 62_B, 62_C, 63_A, 63_B, and 63_C through the connection part and the low pressure part of the four-way valves 65_A, 65_B, and 65_C.

In the multi-air conditioning system having such an operation structure, the first and second compressors 62_A, 62_B, 62_C, 63_A, 63_B, and 63_C of two or more outdoor units are controlled to maintain the same flow path switching state during cooling or heating operation. do.

3 is a flowchart illustrating a control method of a multi-air conditioning system according to a first embodiment of the present invention.

2 and 3, in the multi-air conditioning system, the four-way valves 65_A, 65_B, and 65_C of each outdoor unit A, B, and C switch according to cooling or heating operation operations (S100). When the first compressors 62_A, 62_C, and 62_C of (A, B, C) start operation, the first high and low pressure differences DP1 of the outdoor units A, B, and C are measured (S102).

Here, the description will be made by dividing the main outdoor unit A and the sub outdoor units B and C among the outdoor units A, B, and C, but the present invention is not limited thereto.

That is, the main outdoor unit A measures the first high and low pressure difference DP1 on the suction side and the discharge side of the first compressors 62_A, 62_C, and 62_C.

Each of the first high and low pressure differences DP1 for the first compressors 62_A, 62_C, and 62_C determines whether or not the set first reference pressure AP1 is exceeded (S104). When the high and low pressure difference DP1 exceeds the first reference pressure AP1, since the four-way valves 65_A, 65_B, and 65_C are normally switched, normal cooling or heating operation is started (S106).

If the first high and low pressure difference DP1 of each of the one or more outdoor units B and C of the outdoor units A, B, and C does not exceed the set first reference pressure AP1, the first of the outdoor units B and C The two compressors 63_B and 63_C are driven and the second high and low pressure difference DP2 is measured (S108).

A second determination is made as to whether the second high and low pressure difference DP2 exceeds the set second reference pressure AP2 (S110), and as a result of the determination, each second high and low pressure difference DP2 is the second reference pressure AP2. ), The four-way valves 65_B and 65_C are normally switched, and the second compressors 63_B and 63_C are stopped (S112). Then, step S106 is executed.

In operation S110, when the second high and low pressure difference DP2 does not exceed the second reference pressure AP2, it is determined whether the outdoor units B and C have been operated for more than a set time, and the operation time is less than the set time. Back to (S108) step (S114)

In operation S114, when the operation time is greater than or equal to the set time, the first compressor 62_A of the outdoor unit A that satisfies the first reference pressure AP1 is stopped or operated at the lowest frequency in operation S116. ).

The third high and low pressure difference DP3 of each of the outdoor units B and C is measured to determine whether the third high and low pressure difference DP3 exceeds the set third reference pressure AP3 (S118). As a result of the determination, when each of the third high and low pressure differences DP3 exceeds the third reference pressure AP3, step S112 is performed.

Here, as a result of the determination, if the third high and low pressure difference DP3 of the outdoor unit C of the outdoor units B and C does not exceed the third reference pressure AP3, the four-way valve 65_C is changed to a switching error. Display and judge (S120), compare the switching error number of the four-way valve (65_C) and the set number of times (S122), if the switching error number and the set number is less than, restart the system (S124), the number of switching error is If the set number of times or more is turned off (S126).

In the control method of the multi-air conditioning system of the present invention, when the four-way valve is not switched due to the difference in the compressor starting time or the foreign matter of the four-way valve when the compressor of each outdoor unit is started, the compressor of the outdoor unit other than the outdoor unit that fails to switch the four-way valve is operated. By operating at an off or minimum frequency, it is possible to increase the success rate of switching of the four-way valve and to secure the differential pressure of the outdoor unit in which the four-way valve switching has failed, thereby improving the stability of the driving cycle and the cooling and heating speeds.

Although the preferred embodiments of the present invention have been described in detail above, those skilled in the art to which the present invention pertains should make the present invention without departing from the spirit and scope of the present invention as defined in the appended claims. It will be appreciated that various modifications or changes can be made. Accordingly, modifications to future embodiments of the present invention will not depart from the technology of the present invention.

1 is a block diagram showing a multi-air conditioning system according to a first embodiment of the present invention.

2 is a block diagram of the outdoor unit side cooling cycle in the multi-air conditioning system according to the present invention.

3 is a flowchart illustrating a control method of a multi-air conditioning system according to a first embodiment of the present invention.

Claims (7)

A first determination step of determining whether the first high or low pressure difference exceeds the first reference pressure by measuring the four high and low pressure differences of each outdoor unit after the four-way valve of each outdoor unit is switched and the first compressor is operated; In the first determining step, measuring the second high and low pressure difference after operating the second compressor of the outdoor unit if the first high and low pressure difference of at least one outdoor unit does not exceed the first reference pressure; A second determination step of determining whether the second high and low pressure difference exceeds a second reference pressure until the first and second compressors are operated for a preset time; In the second judging step, operating the first compressor of the outdoor unit in which one of the first and second high and low pressure differences is secured if the second high and low pressure difference does not exceed the second reference pressure; A third determination step of measuring a third high and low pressure difference of the outdoor unit and determining whether the third high and low pressure difference exceeds a third reference pressure; And In the third determination step, if the third high and low pressure difference does not exceed a third reference pressure is determined as a switching error of the four-way valve and the control method of a multi-air conditioning system comprising the step of turning off or restarting the system. The method of claim 1, And in the first determination step, determining that the four-way valve is normally switched when the first high and low pressure difference exceeds the second reference pressure. The method of claim 1, wherein the measuring step, If the first high or low pressure difference of the at least one outdoor unit does not exceed the first reference pressure, the second air conditioner of the outdoor unit, wherein the second compressor of the outdoor unit of which the first high and low pressure difference is the lowest among the at least one outdoor unit is operated. Control method of the system. The method of claim 1, And in the second determination step, stopping the second compressor if the second high and low pressure difference exceeds the second reference pressure. The method of claim 1, wherein the operation control step, And controlling the first compressor of the outdoor unit having one of the first and second high and low pressure differentials to a minimum frequency or to stop operation. The method of claim 1, wherein the restarting step, And in the third determination step, stopping the second compressor when the third high and low pressure difference exceeds the third reference pressure. The method of claim 1, wherein the restarting step, Measuring the number of errors of the four-way valve, and if the error number is more than the set number of times, turning off the system, and if the error number is less than the set number of times, restarting the system. Way.

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